Data Columns

A column definition (MRT_ColumnDef<TData>) describes one column. Define the array once, outside any reactive code.

const columns: MRT_ColumnDef<Person>[] = [
  { accessorKey: 'firstName', header: 'First Name' },
  { accessorKey: 'address.city', header: 'City' }, // nested data: dot notation
  {
    accessorFn: (row) => `${row.firstName} ${row.lastName}`,
    id: 'fullName', // an id is required with accessorFn
    header: 'Full Name',
  },
];

Custom cells, headers and footers

Cell, Header, Footer, Edit and Filter are snippets. Their capital letter keeps them apart from the plain-text header and footer options.

{#snippet salary({ renderedCellValue }: { renderedCellValue: unknown })}
  <strong>${Number(renderedCellValue).toLocaleString()}</strong>
{/snippet}

{#snippet total({ table }: { table: MRT_TableInstance<Person> })}
  Total: {table.getRowModel().rows.length}
{/snippet}

<ShadcnSvelteTable
  options={{
    columns: [
      { accessorKey: 'salary', header: 'Salary', Cell: salary, footer: 'Salary', Footer: total },
    ],
    data,
  }}
/>

renderedCellValue is the cell’s raw value. Match highlighting from filters applies to built-in cells, so a custom Cell is responsible for its own markup.

Sizing

Option	Meaning
size	Width in pixels (default 180)
minSize	Smallest width when resizing (default 40)
maxSize	Largest width when resizing (default 1000)
grow	With layoutMode: 'grid' or 'grid-no-grow', let the column take up remaining space

Change the defaults for every column with the defaultColumn option.

Header groups

Nest columns with columns to create grouped headers:

const columns: MRT_ColumnDef<Person>[] = [
  {
    header: 'Name',
    columns: [
      { accessorKey: 'firstName', header: 'First Name' },
      { accessorKey: 'lastName', header: 'Last Name' },
    ],
  },
];

Display columns

Select, row numbers, expand, actions, drag and pin columns are added for you when you enable their features, with ids like mrt-row-select. Customize one through displayColumnDefOptions, or change all of them with defaultDisplayColumn.

options={{
  columns,
  data,
  enableRowSelection: true,
  displayColumnDefOptions: { 'mrt-row-select': { size: 100 } },
}}